EXT4-fs: Quota format mount options ignored when QUOTA feature is enabled
ext4 filesystem being mounted at /67/bus supports timestamps until 2038-01-19 (0x7fffffff)
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.84/4626 is trying to acquire lock:
ffff88805b94cce8 (&dquot->dq_lock){+.+.}-{3:3}, at: dquot_commit+0x5a/0x410 fs/quota/dquot.c:535

but task is already holding lock:
ffff88805b8cd2c8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&ei->i_data_sem/2){++++}-{3:3}:
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       ext4_map_blocks+0x338/0x1a90 fs/ext4/inode.c:606
       ext4_getblk+0x1c5/0x720 fs/ext4/inode.c:892
       ext4_bread+0x26/0x170 fs/ext4/inode.c:948
       ext4_quota_read+0x17f/0x380 fs/ext4/super.c:7182
       read_blk fs/quota/quota_tree.c:61 [inline]
       find_tree_dqentry+0x1cc/0xf40 fs/quota/quota_tree.c:671
       find_tree_dqentry+0x6ac/0xf40 fs/quota/quota_tree.c:698
       find_tree_dqentry+0x6ac/0xf40 fs/quota/quota_tree.c:698
       find_tree_dqentry+0x6ac/0xf40 fs/quota/quota_tree.c:698
       find_dqentry fs/quota/quota_tree.c:716 [inline]
       qtree_read_dquot+0x59a/0x880 fs/quota/quota_tree.c:736
       v2_read_dquot+0xc0/0x110 fs/quota/quota_v2.c:336
       dquot_acquire+0x152/0x520 fs/quota/dquot.c:491
       ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6837
       dqget+0x713/0xbb0 fs/quota/dquot.c:1013
       __dquot_initialize+0x324/0xd00 fs/quota/dquot.c:1542
       ext4_process_orphan+0x4c/0x2e0 fs/ext4/orphan.c:327
       ext4_orphan_cleanup+0xdfe/0x1650 fs/ext4/orphan.c:472
       __ext4_fill_super fs/ext4/super.c:5574 [inline]
       ext4_fill_super+0x6f0c/0x78f0 fs/ext4/super.c:5693
       get_tree_bdev+0x3e6/0x610 fs/super.c:1377
       vfs_get_tree+0x88/0x270 fs/super.c:1584
       do_new_mount+0x247/0xa40 fs/namespace.c:3078
       do_mount fs/namespace.c:3421 [inline]
       __do_sys_mount fs/namespace.c:3629 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3606
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&s->s_dquot.dqio_sem){++++}-{3:3}:
       down_read+0x42/0x2d0 kernel/locking/rwsem.c:1520
       v2_read_dquot+0x4a/0x110 fs/quota/quota_v2.c:335
       dquot_acquire+0x152/0x520 fs/quota/dquot.c:491
       ext4_acquire_dquot+0x2e3/0x4a0 fs/ext4/super.c:6837
       dqget+0x713/0xbb0 fs/quota/dquot.c:1013
       __dquot_initialize+0x3a9/0xd00 fs/quota/dquot.c:1542
       ext4_create+0x92/0x470 fs/ext4/namei.c:2878
       lookup_open fs/namei.c:3533 [inline]
       open_last_lookups fs/namei.c:3601 [inline]
       path_openat+0x11b9/0x2f10 fs/namei.c:3831
       do_filp_open+0x1ee/0x420 fs/namei.c:3861
       do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
       do_sys_open fs/open.c:1336 [inline]
       __do_sys_creat fs/open.c:1414 [inline]
       __se_sys_creat fs/open.c:1408 [inline]
       __x64_sys_creat+0x8c/0xb0 fs/open.c:1408
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&dquot->dq_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3095 [inline]
       check_prevs_add kernel/locking/lockdep.c:3214 [inline]
       validate_chain kernel/locking/lockdep.c:3830 [inline]
       __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
       lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5678
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
       dquot_commit+0x5a/0x410 fs/quota/dquot.c:535
       ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817
       mark_dquot_dirty fs/quota/dquot.c:400 [inline]
       mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440
       __dquot_alloc_space+0x5f6/0xe50 fs/quota/dquot.c:1777
       dquot_alloc_space_nodirty include/linux/quotaops.h:293 [inline]
       dquot_alloc_space include/linux/quotaops.h:306 [inline]
       dquot_alloc_block include/linux/quotaops.h:330 [inline]
       ext4_mb_new_blocks+0xf55/0x44d0 fs/ext4/mballoc.c:5740
       ext4_ext_map_blocks+0x18d1/0x6640 fs/ext4/extents.c:4361
       ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681
       ext4_alloc_file_blocks+0x378/0xb60 fs/ext4/extents.c:4545
       ext4_fallocate+0x9ce/0x2000 fs/ext4/extents.c:4832
       vfs_fallocate+0x57b/0x6f0 fs/open.c:323
       ksys_fallocate fs/open.c:346 [inline]
       __do_sys_fallocate fs/open.c:354 [inline]
       __se_sys_fallocate fs/open.c:352 [inline]
       __x64_sys_fallocate+0xbd/0x100 fs/open.c:352
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &dquot->dq_lock --> &s->s_dquot.dqio_sem --> &ei->i_data_sem/2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ei->i_data_sem/2);
                               lock(&s->s_dquot.dqio_sem);
                               lock(&ei->i_data_sem/2);
  lock(&dquot->dq_lock);

 *** DEADLOCK ***

4 locks held by syz.0.84/4626:
 #0: ffff88807be3a460 (sb_writers#4){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3026 [inline]
 #0: ffff88807be3a460 (sb_writers#4){.+.+}-{0:0}, at: vfs_fallocate+0x4ee/0x6f0 fs/open.c:322
 #1: ffff88805b8cd440 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: inode_lock include/linux/fs.h:764 [inline]
 #1: ffff88805b8cd440 (&sb->s_type->i_mutex_key#9){++++}-{3:3}, at: ext4_fallocate+0x219/0x2000 fs/ext4/extents.c:4806
 #2: ffff88805b8cd2c8 (&ei->i_data_sem/2){++++}-{3:3}, at: ext4_map_blocks+0x914/0x1a90 fs/ext4/inode.c:674
 #3: ffffffff8cc75048 (dquot_srcu){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8cc75048 (dquot_srcu){....}-{0:0}, at: srcu_read_lock include/linux/srcu.h:165 [inline]
 #3: ffffffff8cc75048 (dquot_srcu){....}-{0:0}, at: __dquot_alloc_space+0x16e/0xe50 fs/quota/dquot.c:1741

stack backtrace:
CPU: 0 PID: 4626 Comm: syz.0.84 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3095 [inline]
 check_prevs_add kernel/locking/lockdep.c:3214 [inline]
 validate_chain kernel/locking/lockdep.c:3830 [inline]
 __lock_acquire+0x2d18/0x7c40 kernel/locking/lockdep.c:5063
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5678
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x12d/0xae0 kernel/locking/mutex.c:747
 dquot_commit+0x5a/0x410 fs/quota/dquot.c:535
 ext4_write_dquot+0x1f0/0x360 fs/ext4/super.c:6817
 mark_dquot_dirty fs/quota/dquot.c:400 [inline]
 mark_all_dquot_dirty+0xf9/0x400 fs/quota/dquot.c:440
 __dquot_alloc_space+0x5f6/0xe50 fs/quota/dquot.c:1777
 dquot_alloc_space_nodirty include/linux/quotaops.h:293 [inline]
 dquot_alloc_space include/linux/quotaops.h:306 [inline]
 dquot_alloc_block include/linux/quotaops.h:330 [inline]
 ext4_mb_new_blocks+0xf55/0x44d0 fs/ext4/mballoc.c:5740
 ext4_ext_map_blocks+0x18d1/0x6640 fs/ext4/extents.c:4361
 ext4_map_blocks+0x9d7/0x1a90 fs/ext4/inode.c:681
 ext4_alloc_file_blocks+0x378/0xb60 fs/ext4/extents.c:4545
 ext4_fallocate+0x9ce/0x2000 fs/ext4/extents.c:4832
 vfs_fallocate+0x57b/0x6f0 fs/open.c:323
 ksys_fallocate fs/open.c:346 [inline]
 __do_sys_fallocate fs/open.c:354 [inline]
 __se_sys_fallocate fs/open.c:352 [inline]
 __x64_sys_fallocate+0xbd/0x100 fs/open.c:352
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff6e9f9e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd897991b8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007ff6ea225fa0 RCX: 00007ff6e9f9e159
RDX: 0000000000000bf1 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007ff6ea03506b R08: 0000000000000000 R09: 0000000000000000
R10: 00000000020003fe R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff6ea225fac R14: 00007ff6ea225fa0 R15: 00007ff6ea225fa0
 </TASK>